biology presentations for a-level, in multimedia james bowles, 2001
DESCRIPTION
BIOLOGY PRESENTATIONS FOR A-LEVEL, IN MULTIMEDIA JAMES BOWLES, 2001. LEFT CLICK OR PRESS SPACE BAR TO ADVANCE, PRESS P BUTTON TO GO BACK, PRESS ESC BUTTON TO END. ‘A’ Level Biology. Protein Synthesis. The Genetic Code. The sequence of bases determines the order of amino acids in a protein. - PowerPoint PPT PresentationTRANSCRIPT
1BIOLOGY PRESENTATIONSFOR A-LEVEL, IN MULTIMEDIA
JAMES BOWLES, 2001
BIOLOGY PRESENTATIONSFOR A-LEVEL, IN MULTIMEDIA
JAMES BOWLES, 2001
LEFT CLICK OR PRESS SPACEBAR TO ADVANCE, PRESS P BUTTONTO GO BACK, PRESS ESC BUTTON TO END
LEFT CLICK OR PRESS SPACEBAR TO ADVANCE, PRESS P BUTTONTO GO BACK, PRESS ESC BUTTON TO END
2
‘A’ Level Biology
‘A’ Level Biology
Protein SynthesisProtein Synthesis
3The Genetic CodeThe Genetic CodeThe sequence of bases The sequence of bases determines the order of determines the order of amino acids in a proteinamino acids in a protein
4The Genetic CodeThe Genetic Code
The code is read in The code is read in TripletsTriplets of of basesbases
This gives 64 combinations of This gives 64 combinations of the 4 basesthe 4 bases
UU AA AA GG CC GG UU AA UU UU GG GG CC AA UU
5
Each triplet is read as a discrete Each triplet is read as a discrete unitunit
The Genetic CodeThe Genetic Code
It is a It is a non-overlappingnon-overlapping code code
UU AA AA GG CC GG UU AA UU UU GG GG CC AA UU
6
It is a It is a DegenerateDegenerate code code
The Genetic CodeThe Genetic Code
GG UU UU GG UU CC GG UU AA GG UU GG
ValineValineMost amino acids have more than Most amino acids have more than
one triplet coding for themone triplet coding for them
7
There is also punctuation in the There is also punctuation in the codecode
The Genetic CodeThe Genetic Code
UU AA AA UU AA GG UU GG AA
Stop codeStop code
8
The code is The code is universaluniversal
The Genetic CodeThe Genetic Code
Codons Codons code for code for the same the same
amino acid amino acid in all in all
organismsorganisms
9
Protein synthesis occurs in three Protein synthesis occurs in three stages:stages:
Protein SynthesisProtein Synthesis
1.1.TranscriptionTranscription
2.2.Activation of Amino AcidsActivation of Amino Acids
3.3.TranslationTranslation
10
Part of the DNA molecule Part of the DNA molecule unwindsunwinds
TranscriptionTranscription
11
RNA polymerase attaches at a RNA polymerase attaches at a start codonstart codon
TranscriptionTranscription
12
RNA polymerase moves along RNA polymerase moves along the DNA catalysing the the DNA catalysing the production of mRNAproduction of mRNA
TranscriptionTranscription
13
At the stop codon the RNA At the stop codon the RNA polymerase and mRNA detach polymerase and mRNA detach
from the DNAfrom the DNA
TranscriptionTranscription
14
UU AA CC
Activation of Amino AcidsActivation of Amino Acids
Amino Acids Amino Acids combine with combine with
tRNAtRNA
MeMett
15
UU AA CC
Activation of Amino AcidsActivation of Amino Acids
This process This process utilises utilises specific specific
enzymes and enzymes and ATP is ATP is
hydrolysedhydrolysed
MeMett
16TranslationTranslation
AA UU GG GG CC GG UU AA UU UU GG GG CC AA UU
A ribosome A ribosome attaches to a attaches to a
length of length of mRNAmRNA
17
tRNA with tRNA with corresponding corresponding anticodon fits anticodon fits
in the ribosomein the ribosome
TranslationTranslation
AA UU GG GG CC GG UU AA UU UU GG GG CC AA UU
MetMet
UU AA CC
MetMet
UU AA CC
MetMet
UU AA CC
MetMet
UU AA CC
MetMet
UU AA CC
18
A second piece A second piece of tRNA fits of tRNA fits
into the into the ribosomeribosome
TranslationTranslation
AA UU GG GG CC GG UU AA UU UU GG GG CC AA UU
MetMet
UU AA CC
CC GG CC
AlaAla
CC GG CC
AlaAla
CC GG CC
AlaAla
CC GG CC
AlaAla
19
A peptide bond A peptide bond forms between forms between the amino acidsthe amino acids
TranslationTranslation
AA UU GG GG CC GG UU AA UU UU GG GG CC AA UU
MetMet
UU AA CC CC GG CC
AlaAla
20
The ribosome
moves along one
codon
TranslationTranslation
AA UU GG GG CC GG UU AA UU UU GG GG CC AA UU
MetMet
UU AA CC CC GG CC
AlaAla
CC GG CC
21
The first The first piece of piece of tRNA is tRNA is releasedreleased
TranslationTranslation
AA UU GG GG CC GG UU AA UU UU GG GG CC AA UU
MetMet
CC GG CC
AlaAla
UUAA CC
UUAA CC
UUAA CC
CC GG CC
22
The 1The 1stst amino acid amino acid remains in remains in
placeplace
TranslationTranslation
AA UU GG GG CC GG UU AA UU UU GG GG CC AA UU
MetMet
CC GG CC
AlaAla
CC GG CC
23
The process The process is repeatedis repeated
TranslationTranslation
AA UU GG GG CC GG UU AA UU UU GG GG CC AA UU
MetMet
CC GG CC
AlaAla
AA UU AA
TyrTyr
AA UU AA
TyrTyr
AA UU AA
TyrTyr
AA UU AA
TyrTyr
CC GG CC
24